One obvious benefit of OVH compared to Hetzner is the S3 storage, the Kubernetes framework and a number of other services provided by OVH, don't think Hetzner would provide those services.
Hetzner's Object Storage does not seem API complete and it was released only recently.
Long time Hetzner user, but I would not trust new system (S3 storage) in this case for things beyond playground and tests until it has at least couple of years in production - Hetzner just made it public in ~ Nov 2024.